Pump



Aug. 11, 1931. E NELSON 1,818,259

PUMP

-1111911 Nov. 24, 192e ttossgese Patented Aug. 11, 1931 C Unire rUMP Application filed November 19,28. Serial No. 321,617.

,This invention relates to pneumatic pumps and has vfor its object the provision of a! new' and improved shape, construction and relation of impeller or fan, and casing, as to produce a maximum air pressure at a given speed.

In the drawings accompanying and forming a. part of this application l have shown my improvements as applied to different types of pneumatic cleaners. Fig. 1 is a vertical central sectional view through part of a can type of vacuum cleaner embodying my improvements; Fig. 2 is a horizontal aXial view through a part of a portable type suction sweeper embodying my improvements; Fig. 3 is a sectional view according to the line 3 3 of Figs. l and 2; and Fig. l illustrates a modiiied form of the device shown A in Fig. l.. y

ln all forms of the invention the fan chamber comprises parallel space-d iiat walls 1 and 2 and a curvilinear side wall 3 connecting them. The wall 1 is formed with a circular recess 4 in which is rotatably mounted the and convexed towards the direction of rotation; and I have also found it advantageous to have the blade so mounted that the arc of such conveXity shallfpass through the shaft 6 as shown by the dotted line go-p in Fig. 3.

l have found it of distinct importance that the side wall be made oblong or ova-l in shape, its minor dimension being slightly greater than the diameter of the impeller, and its major direction being sufliciently greater than the minor dimension to produce two chambers at opposite sides of the impeller, the outlet 8 communicating with one of these chambers and the inlet 9 being formed in the wall 2 opposite the impeller. For convenience of description l' have in Fig. 3 illustrated the major aXis A-B and the minor circular disk 5 constituting' the back of the axis C-D intersecting at the fan shaft G, and thereby dividing the side wall into four arcuate sections; although it is not necessary that the same be divided exactly here or that the shaft be located on the axes except to the extent hereafter described. Excellent rcsults are obtained when this chamber is an ellipse but l iind my best results by making the sections A-C and i-D of parabolic shape. rlhe section CB,-BD is here shown as elliptical. I have further found it advantageous .to make one semi-parabola, as A-C, lof smaller size than the other semiparabola A-l) and when this is done, to displace the fan sha-it slightly eccentrically, the edge of the fan or impeller being nearer that sice which is the smaller, and the direction of rotation being such as to cause each blade to sweep past the face of the larger parabola before passing the outlet 8.

lt is also desirable that the chamber from which the Outlet opens should be smaller in total area than the opposite chamber, and that the latter be left without opening.

@wing to the eccentric mounting of the impeller in the chamber the axes lit- B and C-D as drawn do not strictly coincide with the parabolic and elliptic axes, although the same are preferably approximately parallel to the axes shown; or if the axes be dra-wn to coincide, then the shaft G may not belocated on either axis. The smaller Vparabola is indicated by the letters a, m the larger parabola by the letters a, n and the space at s is smaller than the space at 25.

ln the apparatus shown in Fig. 1 my improvements Yare shown as applied to an upright vacuum cleaner comprising an outer receptacle or can 12, the fan chamber being formed in a hollow cover 13 detachably secured thereto, and the motor having ay frame lilcar 1ied by the cover and depending inside they receptacle, being surrounded by a filter cell l5 to allow the escape of air while holding back dust or litter. ln tl e form shown in l? ig. 2, the fan chamber is set with its plane vertical and carried by suitable wheels the forward wall of the fan casing having a collecting nozzle 21, the rearward wall carrying the motor housing 22, and the fan outlet Ar n..

8 being connected to a nalred dust bag 23. In the form shown in Eig. e l have illustrated a sliOht Vmodification of the parts shown in Fig. l, the side wall of the. fan

casing being` cast integral with the top plate l other forms oit 'fan casingsgwbut itjvill'beY understood that it is not necessary to employ at one time all the relinementsherein described and that changes inndetail can be made so that l do not limit myself in any wise except specilically recited in my sev eral claiuis which l desire may be construed each iiidQiLndently of limitations contained in other claims; and t'urthermore I do not limit my improvements to use in vacuum cleaners since various features of the same are applicable to other kinds o't'tans and blowers.

Having thus described my invention what I claim is: i

l. A centrit'ugaLpump tor aeriform fluids ot the type having a iian and a casing, characterizedeby the casing being' of oblong shape and having two chambers oneat each side ot the fan and in the same plane therewith, and a single outlet openingY which communicates with one Yof said chambers.

.2. A centri uoal pump for aeritorm vfluids of the type having a tan and a casing, characterized bythe tan chamber being ot oblong Oval shape with the fan located between its ends and dening therewith two chambers of` unequal size, the smaller lhaving an outlet opening. i f2 3. A centrifugal pump for aeriform fluids of the type having a tan and a casing, charac- Y terizcd by the tan chamber bein of oblong oval shape with the iian located between its ends and deiimng therewith two chambers in the same plane with said Jian, the tanV being closer to one side of said casing than to the other and one ot said chambers having an i outlet.

4. A centrifugal pump for aeriiform fluids ofthe type having a tan and a casing, characterized by the walls oi" the casing conforming in f p a rt substantially to segment ot a parabola and the outlet being near the vertex of such parabola. n t

5. YA centrifugal pump tor aerit-orm iluids oit the type having Vtan and a casing, characterized by the walls ot the casing conforming in part to the portions of two para-bolas each portion eilt-ending from substantially the vertex to a distance at one side of the major axis.

6. Aentritugal pump for aeriiorm fluids ot' the type having a tan and a. casing, characterized by the walls of the casing conformiisfzs Y i Y 'f n ing in part to the portions at one side of the major axis of two parabolas of unequal size.

7. A centrifugal pump for aeriform fluids of the type having a fan and accasing, characterizedfby the walls of the casing having two adjacent quadrantalfsegments, each conforming substantially to a semi parabola, and theV two remaining quadrants conforming substantialiy each to aquarter ellipse, the fan being located nearer to the sides ot the casing than to the ends so as to define two chambers of which the smaller is that defined by the parabolic segments, and an outlet leading from such smaller chamber. f

8. Areentriiugal pump ton aeriform fluids oi the type having a fan and a casing, characterized by the walls ot the casing having two adjacent quadrantal segments, each conforming substantially to a semi parabola, and the two remaining quadrants conforming substantially each to a quarter ellipse, the fan being located nearer to both sides of said casing than to either end and nearer to one side than to the other, there being an outlet from that end o'lf the casing which has the parabolic side port-ions.

9. A centrifugal pump for aeriorm fluids of the type having a tan and a casing, characterized by the walls of the casing having two adjacent quadrant-al segments, each con forming substantially to a semi parabola, and the two remaining quadrants conforming substantially each to a quarter ellipse, one parabola being smaller than the other, the tan being located nearer to that side of the casing which represents the smaller parabola., and an outlet leading from that part ot' the casing interior which is nearest the apices of said parabolas.

in testimony whereof I hereunto affix my signature.

EDVIN JUELSON. 

